Diffusion transfer reversal processor



14, 1970 J. E. HOLLEY 3,505,944

DIFFUSION TRANSFER REVERSAL PROCESSOR Filed July 5, 196'? 2 Sheets-Sheet 1 4-- 4 M a I log 10B 3, lll I'M I22 no 1 l "4% 22 INVENTOR. 114/155 5'. Haiti? 2 Sheets-Sheet 2 JITTORNE'Y April 14, 1970 J. E. HOLLE Y DIFFUSION TRANSFER REVERSAL PROCESSOR Filed my 5, i967 BYIJJ United States Patent 1 Claim ABSTRACT OF THE DISCLOSURE A diffusion transfer reversal processor having roller applicators for surface wetting of the negative, the positime remaining dry except to the extent that it is moistened by contact with the moistened surface of the negative. The processor has a first guide mechanism to introduce the negative into a processing solution tank and transport and applicator rollers to move the negative sheet through the processing solution tank while wetting its emulsion side only. The processor also has a second guide mechanism to guide the negative out of the processing solution tank and into the nip of squeeze rollers and a third guide mechanism to guide the positive sheet into the nip of the squeeze roller to bring the positive and negative into moist contact.

BACKGROUND OF THE INVENTION Field of the invention The history of this art commenced with Rott Patent 'No. 2,352,014 which issued on June 20, 1944 on an application filed July 21, 1941. This patent disclosed the diffusion transfer reversal process. The negative and positive were both immersed in a processing solution following exposure of the negative and before diffusion from the negative to the positive in a pressing operation. Complete immersion of the negative and positive sheets is shown for example in Agfa French Patent No. 879,995 issued Dec. 10, 1942, Eisbein Patent No 2,657,618 issued on Nov. 3, 1953 and Boeger German Patent No. 969,482 issued June 4, 1958 (filed May 3, 1950).

Description of the prior art In a subsequent development of the art only the negative was immersed in the processing solution, the positive remaining dry. This method is shown for example in Ozalid British Patent No. 699,085 published Oct. 28, 1953 on an application filed July 14, 1950, and Eisbein Patent No. 2,664,801 issued on Jan, 5, 1954 on an application filed Mar. 19, 1951.

In a further development of the art the negative alone or both the negative and positive were surface wetted, neither being immersed in the processing solution. Illustrative of the patents which show surface wetting of both sheets are Zindler British Patent No. 987,506 published Mar. 31, 1965, Dick British Patent No. 1,020,435 published Feb. 16, 1966 and Maillard French Patent No. 1,437,584 issued on Mar. 28, 1966. Illustrative of the patents in which surface wetting is applied to the negative sheet only in Schaum Patent No. 3,233,534 issued Feb. 8, 1966.

SUMMARY OF THE INVENTION The present invention is of a diffusion transfer reversal processor in which only the negative is surface wetted. The positive remains dry until it is moistened by contact with the moistened surface of the negative. The positive remains outside of the processing section of the machine at all times and it is outside of the processing section that the diffusion transfer process takes place,

3,505,944 Patented Apr. 14, 1970 There are a number of features in the present invention which are not shown in the prior art. One such feature resides in the use of a plurality of applicator rolIers to insure adequate wetting of the coated side of the negative. Another feature resides in the surface wetting of the applicator rollers themselves. Dick British Patent No. 1,020,435, for example, shows a single applicator roller half immersed in the processing solution (FIGURE 1) and when two such applicator rollers are employed (FIGURE 3) one of them is virtually entirely immersed in the solution. In Schaum Patent No. 3,233,534 a single applicator roller wets the negative sheet only and it is noted that substantially half of said applicator roller is immersed in the processing liquid.

The present invention seeks to achieve economy of operation by surface wetting both the applicator rollers and the negative, at the same time achieving a relatively dry positive both during and immediately following the transfer process. Only small quantities of the processing solution are stored in the machine and small quantities may be used to replenish the supply. Oxidation is held to a minimum.

An object of this invention is the provision of a relatively simple, inexpensive processor which may be used in the home and in small ofiices where large and expensive oflice copying equipment is neither needed or economically feasible. 7

A further object of this invention is the provision of a processor of the character described which is relatively compact in its proportions so that it will occupy a relatively small space, said processor being provided with removable parts which may readily be assembled or set up in operative form. Conversely it may readily be disassembled for storing purposes. An important feature resides in the ease of disassembly of its component sec tions so that its several components may be made readily accessible for cleaning, replacement and other purposes.

BRIEF DESCRIPTION OF THE DRAWING FIGURE 1 is a front view of a diffusion transfer reversal processor made in accordance with the principles of this invention.

FIGURE 2 is a side view thereof.

FIGURE 3 is an opposite side view thereof.

FIGURE 4 is an enlarged sectional view taken on the line 4-4 of FIGURE 1.

FIGURE 5 is an enlarged fragmentary sectional view on the line 5-5 of FIGURE 3.

FIGURE 6 is a view of one of the two gear drive mechanisms of the machine.

FIGURE 7 is a view of the other gear drive mechanism of the machine, said view being a section on the line 7-7 of FIGURE 5.

DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION The diffusion transfer reversal processor which is herein claimed is provided with a base 10 which comprises a bottom wall 12, a pair of side walls 14, and a pair of end walls 16. A tie rod 18 bridges side walls 14 and holds them in fixed relation to each other. Side walls 14 are shown to be non-parallel upper and lower edges, but this is purely a matter of design and is not a critical element of the invention.

Tank 20 is removably mounted on base 10. It rests on bottom wall 12 and is positioned in place thereon by means of side walls 14 and end walls 16. Tank 20 may be located in place on base 10 by means of latches 22 engaging brackets or keepers 24 on side walls 14. Tank 20 is of generally rectangular configuration, comprising a bottom wall 26, a back wall 28, a front wall 30, a pair of end walls 32 and 34, respectively, and a top wall or cover 36. A horizontal slot 38 is formed in back wall 28 and another horizontal slot 40 is formed in front wall 30*. The tank is adapted to receive a processing or developing liquid D, and screw means 41 or the like are provided to secure the cover to the end walls of the tank in order to confine the developing solution therein and to resist or minimize oxidation or other forms of deterioration of said developing liquid.

Slots 38 and 40 are provided for ingress and egress of negative sheets N or the like. This will become more clearly apparent from the description of the method of operation of this machine, which will shortly be set forth.

It will now be noted that, removably mounted within tank 20 is a pair of oppositely disposed plates 42 and 44, which are situated adjacent and in parallel relation to the end walls 32 and 34 of the tank. Secured to plates 42 and 44 and helping to support them in fixed relation to each other is a generally corrugated or striated strip 50, whose end portions are bent downwardly and secured to said end walls 42 and 44 by means of screws 52 or other suitable fastening means. These plates serve as supports for the applicator rollers of the machine, and their respective shafts and bearings and their drive means.

Specifically, bearings 54, 56, 58, 60 and 62 are provided in end walls 42 and 44. These bearings support shafts 64, 66, 68, 70 and 72. Secured to said shafts are gears 74, 76, 78, 80 and 82, respectively. Rubber coverings 86, 88, 90 and 92 are provided on shafts 66, 68, 70 and 72, respectively, thereby forming two pairs of upper and lower rollers, as best shown in FIGURE 4.

Lower rollers 90 and 92 dip into the processing or developing solution D and serve as the applicator rollers of the machine. Upper rollers 86 and 88 serve as opposing back-up rollers. It is between applicator rollers 90 and 92 on the one hand and opposing rollers 86 and 8-8 on the other hand that the negative sheet N passes on its way through the machine. The coated side of the negative sheet faces downwardly and makes contact with the two applicator rollers. Since these two rollers are partially immersed in the processing or developing solution, and since they rotate therein as part of the operation of the machine, they pick up and dispose upon the coated side of the negative sheet a metered quantity of the solution. The emulsion on the negative sheet is moistened, but the sheet itself remains dry.

A ramp or slide 100 is provided for the insertion of the negative sheet into the machine. This ramp is a removable, collapsible device which includes a bracket -2 at its back end, a strut 104 pivotally secured to said bracket, a pair of entry limit bars 106, and a pair of sheet guide walls 108. The forward or discharge end of the ramp is inserted through slot 38 in wall 28 of the developer tank. Entry limit bars 106 serve as stop elements to position the forward or discharge end of the ramp relative to the nip of rollers 86 and 90. Strut 104 supports the ramp in its inclined operative position shown in FIGURES 2 and 4.

When a negative sheet N is placed upon ramp 100 (following exposure), it may be pushed down the ramp and through slot 38 to the nip of rollers 86 and 90. Once the sheet is caught between the rollers, it will be drawn through the machine without further manual attention. Rollers 86 and 90 will transport the negative sheet to the nip of rollers 88 and 92, and the latter rollers will move the negative sheet onto and across corrugated or striated 50 and thence through slot 40 and out of the tank. As has above been indicated, rollers 90 and 92 rotate in the processing or developing solution and transfer that solution in metered quantities to the coated side of the negative sheet. Consequently, when the sheet emerges from the tank it is moistened on its coated side (where development occurs), while remaining dry on its opposite side.

The negative sheet is now brought into "contact with positive sheet P, coated side to coated side, and the two sheets are passed between a pair of transfer rollers 110 and 112, as shown in FIGURE 4. These transfer rollers are mounted on shafts 114 and 116, respectively, which are journaled in bearings 118 and 120 carried by side walls 14. Secured to shafts 114 and 116 are gears 122 and 124, respectively. Also secured to shaft 116 is a gear 125. It will be noted in FIGURE 3 that gear 125 is driven by a gear 126 on stud shaft 128, and said gear 126 is in turn driven by another gear 130 on shaft 64.

A curved ramp 140, having sheet guide elements 142, is provided on the forward end of base 12. This curved ramp is located on the outside of the developersolution tank, as FIGURE 4 clearly shows. It conducts positive sheet P to the nip of transfer rollers 110 and 112, and thereby brings the positive sheet into contact with the negative. More specifically, the coated side of the positive sheet faces downwardly upon the forward end of ramp 140, but it faces upwardly after turning back upon itself approximately degrees to move in the same direction as the negative sheet, in order to reach the nip of rollers rollers 110 and 112. Since the coated side of the positive faces upwardly in the nip of the rollers, and the coated side of the negative faces downwarly, there will be a transfer of the image from the negative to the positive under the pressure of the two rollers. A sandwich is thereby formed between the two sheets, and when the sheets are peeled apart a positive image is found to be formed on the positive sheet. This concludes the operation.

The above described machine is intended primarily for use in the home and in relatively small offices and other establishments. It may be manually operated or motor driven, as desired. In either case, the drive shaft is shaft 64, and there are two drive gears thereon, 74 and 130'. Drive gear 74 drives gears 76 and 78, and the latter drives gears 80 and 82. It is by this means that rollers 86, 88, 90 and 92 are caused to rotate in order to transport the negative sheet through the machine. Drive gear 130 drives gear 126, which drives gear 125. Since gear 125 is secured to the same shaft as gear 124, the latter will drive gear 122 in order to cause rotation of the two transfer rollers 110 and 112 as above described. Since all of the rollers, applicator, back-up, and transfer alike, are driven by the same gear system, they are synchronized relative to each other in order to carry the negative sheet through the tank, and the negative and positive sheets between the transfer rollers.

Tank 20 may be supplied with processing or developing solution D through a filler tube 144 having a funnelshaped opening at its upper end and a contricted opening at its lower end. This is an illustrative construction and is intended only to facilitate introduction of the silution into the feeder tube and to direct its discharge flow in a relatively thin, smooth-flowing stream to a predetermined point within the tank.

Cleaning is another problem which the present construction facilitates. The several parts of the machine are assembled in separable sub-assembly groups. Thus the ramp 100, with its bracket 102, strut 104, and elements 106 and 108, constitutes a sub-assembly which may be removed from the rest of the machine. The applicator and back-up rollers 90, 92, 86 and 88 also comprise a sub-assembly in conjunction with their several shafts, gears and supporting plates 42 and 44. This sub-assembly includes corrugated or striated plate 50, whose ends are secured to the two plates 42 and 44. This entire subassembly is removable from tank 20; All that need be done to remove this sub-assembly from the tank is to remove the cover 36 and to lift the sub-assembly out of the tank.

The tank itself may similarly be detached and removed from base 10. This may be done by the simple expedient of opening latches 22, 24, and lifting the tank otf the base. All that would remain on the base, therefore, is the sub-assembly, consisting of the transfer rollers and the curved ramp for the positive sheet.

It Will be understood from all of the foregoing that each sub-assembly may readily be cleaned once it is removed from the machine as a whole. After it is cleaned, it may equally as readily be placed in the machine for further operation.

The foregoing describes a preferred form of the invention, and it will be understood that other forms may be provided, as well as modifications of the illustrated form, Within the broad scope of the appended claims.

What is claimed is:

1. A diffusion transfer reversal processor, comprising:

a Supporting base,

a processing solution tank mounted on said base,

a plurality of applicator and transport rollers rotatably mounted within said tank,

first guide means disposed on one side of the tank for guiding a negative sheet into the tank and into the nip of the applicator and transport rollers,

a pair of squeeze rollers rotatably mounted on said base on the opposite side of the tank,

second guide means extending from said applicator and transport rollers in the direction of said squeeze rollers for guiding the negative sheet out of the tank and into the nip of the squeeze rollers,

third guide means mounted on the base on said opposite side of the tank for guiding a positive sheet into the nip of the squeeze rollers, said third guide means comprising a chute having a flat horizontal section adapted to receive a positive sheet and a discharge end which defines a return curve adapted to direct the positive sheet into contact with the negative sheet while moving in the same direction toward the inlet side of the nip of the squeeze rollers, and

drive gear means interconnecting and driving all of said rollers, synchronizing their rotation,

whereby the negative sheet is transported through the tank, where it is moistened by the applicator rollers and then brought into contact with the positive sheet at the nip of the squeeze rollers which press the two sheets together and cause them to emerge in sandwich form References Cited UNITED STATES PATENTS 3,107,596 10/1963 Arnold et al. 9594 XR 3,142,241 7/ 1964 Limberger. 3,242,843 3/ 1966 Tillotson et al. 95-89 R FOREIGN PATENTS 1,334,450 7/ 1963 France.

632,823 12/ 1949 Great Britain. 914,120 12/ 1962 Great Britain.

25 NORTON ANSHER, Primary Examiner R. P. GREINER, Assistant Examiner 

